JPS61134133A - Light repeater - Google Patents

Abstract

PURPOSE:To obtain a light repeater that can avoid excessive prevention by making a light source controlling circuit stop operation of a light source of the first light transmitting circuit responding to light source deterioration information and operate a light source of plural light transmitting circuits. CONSTITUTION:Light waveform value is detected from a part of forward light signal of a light source 2 of a light transmitting circuit OS1 or from backward light signal by a photoelectric element 3 and a peak detecting circuit 7, and a voltage VEX corresponding to the value is obtained. When an extinction ratio deteriorates and the VEX exceeds a predetermined voltage VR2, deterioration information CONT(1,B) of the light transmitting circuit OS1 is sent out from a voltage comparator 8 to a light source controlling circuit 9. The light source controlling circuit 9 controls a transistor that supplies a pulse current and bias current of light source 2 of the light transmitting circuit OS1 by a light controlling signal CONT(1,A) of the light transmitting circuit OS1, and turns off the light source 2, and conversely, turns on the light source of a light transmitting circuit OS2 by a light source controlling signal CONT(2,A) of the light transmitting circuit OS2.

Description

【発明の詳細な説明】 〔技術分野〕 本発明は現用及び複数個の予備の光源を有する光中継器
に関し、とくにその光源切替方式に改良を加えた光中継
器に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical repeater having a working light source and a plurality of standby light sources, and particularly relates to an optical repeater having an improved light source switching method.

〔従来技術〕[Prior art]

従来複数個の光源をもつ光中継器においては、現用光源
の閾値電流を温度特性を補正して監視し、この閾値電流
がある決められた値を越えると、現用光源がら予備光源
へ切替える方式が採用されている。Conventionally, in optical repeaters with multiple light sources, there is a method in which the threshold current of the active light source is monitored by correcting the temperature characteristics, and when this threshold current exceeds a certain value, the active light source is switched to a standby light source. It has been adopted.

閾値電流の増加は、光源の劣化を検出する一つの情報で
はあるが、例えば漏れ電流により閾値電流が増加した場
合、元ファイバ伝送系の特性劣化と必ずしも一致しない
。従って過剰予防となる危険性がおる。An increase in the threshold current is one piece of information for detecting deterioration of the light source, but if the threshold current increases due to leakage current, for example, it does not necessarily match the deterioration of the characteristics of the original fiber transmission system. Therefore, there is a risk of over-prevention.

〔発明の目的〕[Purpose of the invention]

本発明の目的は、この過剰予防音道けることのできる元
中継器を提供することにある。An object of the present invention is to provide a source repeater that can prevent this excessive noise.

〔発明の構広〕[Breadth of invention]

本発明の元中継器は、光源制御回路と、前記光源制御回
路からの光源制御信号、入力信号を入力とするパルス電
流駆動回路、前記光源制御信号を入力とするバイアス回
路、前記パルス電流駆動回路、バイアス回路の出力を合
成する手段、前記合成手段を出力を第一の光出力に変換
する光源、前記光源の光出力を受光して電気信号に変換
する受光素子、前記受光素子の出力ｔ−積分する積分回
路、前記積分回路の出力１第−の基準値と比較して前記
バイアス回路ｔ−、前記第一の光出力のパワー金はぼ一
定にするように制御する比較回路、前記受光素子の出力
のピーク値金検出するピーク検出回路、前記ピーク検出
回路の出力が第二の基準値を越えたとき光源劣化情報を
前記光源制御回路に出力する比較回路を有する第一の光
送信回路と、前記第一の光送信回路と同一機能を有する
複数の光送信回路とを有し、前記光源制御回路が、前記
光源劣化情報に応じて前記第一の光送信回路の前記光源
の動作を停止させ、前記複数の光送信回路の一つの光源
を動作させるようにし九ことを特徴とする。The main repeater of the present invention includes a light source control circuit, a light source control signal from the light source control circuit, a pulse current drive circuit that receives an input signal, a bias circuit that receives the light source control signal as input, and the pulse current drive circuit. , means for combining the outputs of the bias circuits, a light source for converting the output of the combining means into a first optical output, a light receiving element for receiving the optical output of the light source and converting it into an electrical signal, and an output t- of the light receiving element. an integrating circuit that integrates, the bias circuit t- which compares the output of the integrating circuit with a first reference value, a comparison circuit that controls the power of the first optical output to be approximately constant, and the light receiving element. a first optical transmission circuit having a peak detection circuit for detecting a peak value of the output of the peak detection circuit; and a comparison circuit for outputting light source deterioration information to the light source control circuit when the output of the peak detection circuit exceeds a second reference value; , comprising a plurality of optical transmitting circuits having the same function as the first optical transmitting circuit, and the light source control circuit stops the operation of the light source of the first optical transmitting circuit according to the light source deterioration information. and operating one light source of the plurality of optical transmitting circuits.

〔原理と作用〕[Principle and operation]

光源の直接変調では、一般的には第１図に示すように常
にある一定のバイアス電流ＩＢを流しておき、それに信
号パルス電流ＩＰを重畳する。又、光源は温度特性を持
っているためバイアス電流を制御して光出力の安定化を
はかっている。本発明では第１図における光波形０−Ｐ
値Ｐｓｔ−検出し劣化の情報とする。このＰｓは光出力
安定化回路をもつ光送信回路では閾値電流ＩＴＨには依
存せず光源の電気−光ＣＰｙ／Ｉｔ）変換効率に依存す
るものである。従って本発明では、光源の電気−光変換
効率の低下を光源の劣化と判定するつ〔実施例〕 本発明の実施例を第２図に示す。光送信回路０８１の光
源２の前方向光信号の一部、或いは後方向の光信号から
受光素子３、ピーク検出回路７で、前述の光波形０−Ｐ
値ＰＢを検出し、ＰｓＫ対応する電圧ＶΣＸが得られる
。消光比が劣化し、ＶＥＸがある設定石れた電圧ＶＲ２
を越えると、光送信回路０８１の劣化情報Ｃ０ＮＴ　（
１，Ｂ　）が電圧比較器８よシ光源制御回路９へ送出さ
れる。光源制御回路９は、光送信回路０８１の光源制御
信号Ｃ０ＮＴ（１，Ａ）で光送信回路０８１０光源２の
パルス電流及びバイアス電流を供給しているトランジス
タを制御し光源２をＯＦＦ　Ｌ、逆に光送信回路０８２
の光源制御信号Ｃ０ＮＴ（２，Ａ）で光送信回路０８２
の　−光源をＯＮさせる。以下同様の動作で、順次光送
信回路０８２−・・・−光送信回路０８Ｎ−１−光送信
回路０８Ｎと切替る。In direct modulation of a light source, generally a constant bias current IB is kept flowing as shown in FIG. 1, and a signal pulse current IP is superimposed thereon. Furthermore, since the light source has temperature characteristics, the bias current is controlled to stabilize the light output. In the present invention, the optical waveform 0-P in FIG.
The value Pst is detected and used as deterioration information. In an optical transmission circuit having an optical output stabilizing circuit, Ps does not depend on the threshold current ITH but depends on the electrical-optical CPy/It) conversion efficiency of the light source. Accordingly, in the present invention, a decrease in the electrical-to-optical conversion efficiency of a light source is determined to be deterioration of the light source. [Example] An example of the present invention is shown in FIG. The light receiving element 3 and the peak detection circuit 7 convert a part of the forward optical signal from the light source 2 of the optical transmitting circuit 081 or the backward optical signal to the optical waveform 0-P described above.
The value PB is detected and a voltage VΣX corresponding to PsK is obtained. The extinction ratio deteriorates and the setting voltage VR2 with VEX is reduced.
When it exceeds the deterioration information C0NT of the optical transmitter circuit 081 (
1, B) is sent from the voltage comparator 8 to the light source control circuit 9. The light source control circuit 9 controls the transistor that supplies the pulse current and bias current of the light source 2 of the optical transmitter circuit 0810 with the light source control signal C0NT (1, A) of the optical transmitter circuit 081, and turns off the light source 2, and vice versa. Optical transmitter circuit 082
The optical transmitter circuit 082 receives the light source control signal C0NT (2, A).
-Turn on the light source. Thereafter, in the same manner, the optical transmitting circuits 082 - . . . - optical transmitting circuits 08N-1 - optical transmitting circuits 08N are sequentially switched.

〔発明の効果〕〔Effect of the invention〕

本発明によれば過剰予防の危険性がなく、又、閾値電流
の温度特性を補正する必要がなく、ピーク検出回路、電
圧比較器で簡単に構成して予備光源に切替えることが可
能である。According to the present invention, there is no risk of excessive prevention, there is no need to correct the temperature characteristics of the threshold current, and it is possible to switch to a backup light source by simply configuring a peak detection circuit and a voltage comparator.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は周知の光源の特性を示す特性図、第２図は本発
明の一実施例を示すブロック図でめる。 １１・・・・・・光源の電流−光出力電力特性曲線、１
２・・・・・・光源に印加される信号波形、１３・・・
・・・光源の出力波形、１・・・・・・パルス電流駆動
回路、２・・・・・・光源、３・・・・・・バイアス回
路、４・・・・・・受光素子、５・・・・・・積分回路
、６，８・・・・・・電圧比較回路、７・・・・・・ピ
ーク検出回路、９・・・・・・光源制御回路、０８Ｎ・
・・・・・光送信回路Ｎ、Ｃ０ＮＴ（Ｎ、Ａ）・・・・
・・Ｏ８Ｎの光源制御信号、Ｃ０ＮＴ（Ｎ、Ｂ）・・・
・・・Ｏ８Ｎの光源劣化情報。 、−八 代理人　弁理士　　内　原　　　曽　　′（゛−−−１FIG. 1 is a characteristic diagram showing the characteristics of a known light source, and FIG. 2 is a block diagram showing an embodiment of the present invention. 11...Light source current-light output power characteristic curve, 1
2... Signal waveform applied to the light source, 13...
... Output waveform of light source, 1 ... Pulse current drive circuit, 2 ... Light source, 3 ... Bias circuit, 4 ... Light receiving element, 5 ...Integrator circuit, 6,8...Voltage comparison circuit, 7...Peak detection circuit, 9...Light source control circuit, 08N.
...Optical transmitter circuit N, C0NT (N, A)...
・・O8N light source control signal, C0NT(N,B)...
...O8N light source deterioration information. , -8 Agent Patent Attorney Uchihara So ′(゛----1

Claims (1)

【特許請求の範囲】[Claims] 光源制御回路と、前記光源制御回路からの光源制御信号
、入力信号を入力とするパルス電流駆動回路、前記光源
制御信号を入力とするバイアス回路、前記パルス電流駆
動回路、バイアス回路の出力を合成する手段、前記合成
手段を出力を第一の光出力に変換する光源、前記光源の
光出力を受光して電気信号に変換する受光素子、前記受
光素子の出力を積分する積分回路、前記積分回路の出力
を第一の基準値と比較して前記バイアス回路を、前記第
一の光出力のパワーをほぼ一定にするように制御する比
較回路、前記受光素子の出力のピーク値を検出するピー
ク検出回路、前記ピーク検出回路の出力が第二の基準値
を越えたとき光源劣化情報を前記光源制御回路に出力す
る比較回路を有する第一の光送信回路と、前記第一の光
送信回路と同一機能を有する複数の光送信回路とを有し
、前記光源制御回路が、前記光源劣化情報に応じて前記
第一の光送信回路の前記光源の動作を停止させ、前記複
数の光送信回路の一つの光源を動作させるようにしたこ
とを特徴とする光中継器。A light source control circuit, a light source control signal from the light source control circuit, a pulse current drive circuit that receives the input signal, a bias circuit that receives the light source control signal, and the outputs of the pulse current drive circuit and the bias circuit are synthesized. means, a light source that converts the output of the combining means into a first optical output, a light receiving element that receives the optical output of the light source and converts it into an electrical signal, an integrating circuit that integrates the output of the light receiving element, and the integrating circuit. a comparison circuit that compares the output with a first reference value and controls the bias circuit so that the power of the first optical output is approximately constant; and a peak detection circuit that detects the peak value of the output of the light receiving element. , a first optical transmitter circuit having a comparison circuit that outputs light source deterioration information to the light source control circuit when the output of the peak detection circuit exceeds a second reference value; and a first optical transmitter circuit having the same function as the first optical transmitter circuit. a plurality of optical transmitting circuits having a plurality of optical transmitting circuits, the light source control circuit stopping the operation of the light source of the first optical transmitting circuit according to the light source deterioration information, and controlling one of the plurality of optical transmitting circuits. An optical repeater characterized by operating a light source.